One of those FWIW ideas.
We have wireless speakers planted all over the house with the transmitter being fed from the home control computer audio output. I have each speaker powered by a wall wart controlled by an Appliance Module, so Homeseer (or AHP and BVC, HAL, etc) can steer the audio to rooms or outside when needed.
The other day I was thinking this was a partial waste of the "whole house" audio system since it was essentially dedicated exclusively to home control announcements. It would be nice if I could pump audio from a radio or other sound source through all the speakers also.
So I hacked up three miniature stereo extension cords and soldered the ground, left, and right, audio lines of each to a 120v coil, 4 pole, double throw relay.
The common terminals (the armature or switched terminals) of the relay goes to the audio transmitter. The ground, left and right audio from the computer goes to the normally closed (NC) terminals of the relay and the ground, left and right audio from the radio goes to the normally open (NO) terminals of the relay. I soldered a line cord to the relay coil so the relay can be controlled by an Appliance Module.
In the default state (Appliance Module off), computer announcements are heard in the house, but if I want to listen to the radio I just say "Turn on Rush" and Homeseer (or AHP and BVC, etc ) turns on all the the inside speakers and the Appliance Module controlling the relay, which then couples the headphone output from the radio to the wireless speaker transmitter. "Turn off radio" turns off all the speakers and the Appliance Module/relay recouping the home control computer audio back to the transmitter. The four pole relay even has a set of unused terminals so you can wire up some LED indicators through those if you wish.
With a "junk box" Appliance Module, parts are less than $10.
http://www.allelectronics.com/make-a-store/item/4PRLY-120N/4PDT-120VAC-ICE-CUBE-RELAY/1.htmlhttp://www.allelectronics.com/make-a-store/category/117/Cables-3.5mm-Plugs/1.htmlhttp://www.allelectronics.com/make-a-store/item/LCAC-398/6-BLACK-2-CONDUCTOR-POWER-CORD/1.html